The studies' outcomes were nearly evenly split, with 56.2% coming up with positive conclusions and 43.8% reporting negative findings. Four reports were considered “not classifiable.” The researchers wrote that “trial sponsorship did not predict for positive conclusions by phase III authors.”
The study authors noted, however, that “our sample is biased toward positive trials because they are more likely to be discussed by an editorial and because they draw more attention than negative studies.”
In an accompanying editorial, Dr. David Johnson, chairman of the internal medicine department at the University of Texas Southwestern School of Medicine in Dallas, expressed concern about publication bias. “Industry sponsored trials with a positive result are far more likely to be published than are studies with a negative outcome, and when negative trials are published, it is often with a positive spin,” he wrote.
In the report, the authors found that of 20 phase 3 trial reports with negative findings were discussed positively in the study conclusions, and that 15, or 75%, of those study authors had reported conflicts of interest. However, “labeling these findings as biased interpretation by authors is tricky,” the authors wrote. “After analyzing these articles, we felt that, in many cases, the favorable conclusions were pertinent and acceptable.”
The author of the study about conflicts of interest in clinical trials themselves reported no conflicts of interest.
Corresponding author Dr. Rachel Riechelmann, with the Instituto do Câncer do Estado de São Paulo in Brazil, said in an e-mail that the researchers received no funding for the report. It was also disclosed in the report that she has been compensated by Novartis for work in a consulting or advisory role. Other researchers have also received honoraria from AstraZeneca, Merck Serono, Novartis, Roche, and sanofi-aventis. The authors also reported having other research funded by AstraZeneca, Exelixis and Novartis.
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